The overall aim of this investigation is to determine if vasomotor symptoms (VMS; hot flashes and night sweats) are a mechanism for memory changes in the transition from premenopause to perimenopause to postmenopause. The menopausal transition (MT) is associated with subtle declines in processing speed, motor function, verbal fluency and verbal episodic memory1-4. Evidence suggests a direct influence of hormonal transitions on these sexually dimorphic cognitive domains, though the exact mechanism is not known. It has been proposed that vasomotor symptoms (VMS, hot flashes and night sweats), are associated with cognition during the MT, but prior studies have focused exclusively on subjectively reported, but not objectively measured, VMS. The current application builds on prior work from this laboratory demonstrating cognitive declines in the first year after the final menstrual period, and that objectively measured VMS are associated with verbal episodic memory in post-menopausal women. The specific aims are to examine the relationship between objectively measured hot flashes and cognitive function, both immediately and longitudinally across the MT, after accounting for objectively measured sleep. In this study, ambulatory monitoring of VMS and sleep will be incorporated into an ongoing, NIA-funded prospective study of cognitive changes during the MT to evaluate the immediate and cumulative effect of hot flashes on cognition. It is hypothesized that objective VMS will have a negative impact on verbal memory performance in perimenopause and that changes in hot flash frequency will predict changes in verbal memory performance over time. Findings from these studies will inform our understanding of memory dysfunction in the MT and the potential of using VMS as a measure of risk for cognitive decline, which would highlight an important target for therapeutic intervention.